function createRequestObject(){
    var req; 
    try{
        // Firefox, Opera, Safari
        req = new XMLHttpRequest();
    }catch(e){
        // Internet Explorer
        try{
            //For IE 6
            req = new ActiveXObject("Msxml2.XMLHTTP");
        }catch(e){
            try{
                //For IE 5
                req = new ActiveXObject("Microsoft.XMLHTTP");
            }catch(e){
                alert('Your browser is not IE 5 or higher, or Firefox or Safari or Opera');
            }
        }
    }
    return req;
}

//Make the XMLHttpRequest Object
var http = createRequestObject();
function sendRequest(method, url){
    if(method == 'get' || method == 'GET'){
        http.open(method,url,true);
        http.onreadystatechange = handleResponse;
        http.send(null);
    }
}

function handleResponse(){
    if(http.readyState == 4 && http.status == 200){
        var response = http.responseText;
        if(response){
            document.getElementById("container-content").innerHTML = response;
        }
    }
}